Free Online Calculators
TDEE, protein, carbs & fat based on your goal
This macro calculator figures out your Total Daily Energy Expenditure (TDEE) and breaks it down into the right amounts of protein, carbs, and fat for your specific goal โ whether that's losing weight, building muscle, or maintaining. It uses the Mifflin-St. Jeor equation to estimate your basal metabolic rate, then adjusts for your activity level. The result is a clear, personalized daily macro target.
Thanks for your feedback!
Start with your daily calorie target, then split those calories between protein, carbs and fat and convert each share into grams. Protein and carbs supply four calories per gram and fat nine, so dividing each calorie share by that factor gives your gram targets.
It's a split where forty percent of your daily calories come from carbohydrates, forty percent from protein and twenty percent from fat. It's a popular starting point for body recomposition because the high protein share supports muscle while calories stay controlled.
Any calculator based on the Mifflin-St Jeor equation tends to be the closest for most people, since that formula estimates resting metabolic rate more reliably than older Harris-Benedict versions. Accuracy still depends on how honestly you rate your activity level, so treat the output as a starting point and adjust after a few weeks of tracking.
A moderate calorie deficit with a high protein share works best: keep protein high to protect muscle, then divide the rest between carbs and fat according to your preference. There's no single magic ratio โ the deficit drives fat loss, and protein determines how much of that loss is fat rather than lean tissue.
The same macros that drive overall fat loss, because you can't target belly fat through diet โ a calorie deficit with plenty of protein and fibre-rich carbs. Where your body loses fat first is largely genetic, so abdominal fat shrinks as your total body fat drops.
This macro calculator uses the Mifflin-St Jeor equation โ one of the most accurate formulas for estimating your Basal Metabolic Rate (BMR). Your BMR is how many calories your body burns at complete rest. From there, the calculator applies an activity multiplier to find your Total Daily Energy Expenditure (TDEE), which reflects your real-world calorie burn based on how active you are.
Once your TDEE is established, your macronutrient targets โ protein, carbohydrates, and fat โ are distributed based on your selected goal. Protein is set per kilogram of body weight (1.6 g to maintain, 2.0 g to lose, 2.2 g to build), fat is fixed at 25% of your calorie target, and carbohydrates fill the rest. For example, a 30-year-old man (180 cm, 80 kg, moderately active) has a TDEE of 2,759 calories; with the goal "Build muscle" the target is 3,059 calories: 176 g of protein, 85 g of fat and 398 g of carbs per day.
If your goal is to lose weight, the calculator subtracts a fixed 500 calories from your TDEE and sets protein high, at 2.0 g per kg of body weight, to help preserve lean muscle. For an 80 kg person with a 2,000-calorie TDEE, that means 1,500 calories with 160 g of protein per day. Adequate protein prevents muscle loss that often accompanies calorie restriction.
For those looking to maintain weight, macros are set at TDEE with a balanced split that supports energy and recovery. And if you're focused on building muscle, the calculator adds a modest 300 calories to your TDEE and raises protein to 2.2 g per kg, giving your body the raw materials it needs for growth without a large surplus. This approach aligns with what's commonly called IIFYM (If It Fits Your Macros), a flexible dieting strategy that focuses on hitting daily macro targets rather than eating specific "clean" foods.
The question how much protein do I need comes up constantly in fitness communities. Most evidence points to 0.7โ1g of protein per pound of body weight as a practical target for active individuals. A 175-pound person aiming to build muscle would therefore target roughly 140โ175g of protein daily โ something this macronutrient calculator factors in automatically.
Your macro targets are a starting point, not a rigid prescription. Track your intake for 2โ4 weeks using a food logging app, then assess your progress. If your weight isn't moving in the expected direction, adjust calories by 100โ150 per day before making larger changes. Small, consistent tweaks outperform dramatic overhauls every time.
You can use simple-calculator.online to recalculate your macros whenever your weight, activity level, or goal changes. As your body composition shifts, your TDEE changes too โ recalculating every 4โ8 weeks keeps your targets accurate and your progress on track.
BMR (Basal Metabolic Rate) is the number of calories your body needs to function at complete rest โ breathing, circulation, cell repair. TDEE (Total Daily Energy Expenditure) adds your activity level on top of that, giving you a realistic daily calorie target.
The Mifflin-St Jeor equation is considered highly accurate for most adults, but individual metabolism varies. Use your results as a reliable starting estimate and adjust based on real-world progress over several weeks.
This calculator is for informational purposes only and does not replace professional medical or dietary advice. If you have a health condition, eating disorder history, or specific clinical nutrition needs, please consult a registered dietitian or physician before making significant dietary changes.